Manufacture of prussic acid.



UNITED STATES Patented June 20, 1905.

PATENT OFFICE.

WILHELM MUTHBIANN, OF MUNICH, GERMANY, ASSIGNOR TO THE ROESS- LEE. AND FLASSLACHER CHEMICAL CO., OF NE\V YORK, N. Y.

MANUFACTURE OF PRUSSIC ACID.

SPECIFICATION forming part of Letters Patent No. 792,783, datedJ'une 20, 1905.

- Application filed October 17, 1903. Serial No. 177,478.

To all whom, it may concern.-

Be it known that I, VVILHELM MUTHMANN, a subject of the German Emperor, residing at Munich,Bavaria, Germany, have invented certain new and useful Improvements in the Manufacture of Prussic Acid, of which the follo wing is a specification.

Berthelot in the year 1869 (Bulletin (la la Socict O/mhm'que 11, page 446) observed that when powerful sparks from a Ruhmkorfi" induction-coil are passed through a mixture of acetylene and nitrogen prussic acid is produced and carbon is separated, Berthelot obtaining in ninety minutes only one-hundredth part of a gram of prussic acid from one hundred and sixty cubic centimeters of gas mixture. If the prussic acid be absorbed in a pipe by caustic potash, five-sixths of the acetylene is converted into prussic acid in from twelve to fifteen hours. Ethylene and hexane furnished likewise prussic acid when the induction-spark was caused to pass through them. The presence of the prussic acid was, however, only proved qualitatively. Mixter (Americcm Journal of Science, 4th series, Vol. 10, page 229) has also investigated the formation of prussic acid from acetylene and nitrogen and obtained the high temperature required by the explosion of com pressed acetylene in iron bombs. This explosion was caused by an ind action-spark which struck for amoment through the gas mixture. At atmospheric pressure lflixter obtained no prussic acid, because acetylene does not explode at atmospheric pressure. The aforesaid opera tions cannot of course be used for the commercial preparation of prussic acid.

I have found that the yield in prussic acid obtained by Berthelot can be increased fifty times if instead of the spark from an induction-coil an electric flame of high voltage be used and if the mixture of hydrocarbons and nitrogen instead of being exploded in a bomb is blown in the form of a constant current through the flame and the resulting reaction products are constantly removed. This process has the advantage over that of Berthelot that in lieu of the costly acetylene, ethylene, or hexane cheaper hydrocarbons can be used.

Such hydrocarbons are methane and its homologues, the hydrocarbons escaping from the earth, illuminating-gas composed, essentially, of two per cent. carbonic acid, four per cent. heavy carbureted hydrogen, eight per cent. carbon monoxid, forty-nine per cent. hydrogen, and thirtyseven per cent. methane, gases from coke works, mineral oils and the products of their distillation, and also benzcne, toluene, naphthalene, and other products from the distillation of tar. If these hydrocarbons or their vapors be mixed with nitrogen or with nitrogen and hydrogen and the mixture be passed through a high-voltage flame, as much prussic acid is produced as will render the process suitable for the commercial preparation of prussic acid. Hydrogen is added in cases where heavy hydrocarbons, liable to give a deposit of soot, are used. The prussic acid may he condensed or absorbed by alkalies, or it may be worked into other marketable productsby saponification in hot lyes.

The following are examples of ways of carrying out the process.

Example I: Equal parts of nitrogen and illuminating gas are passed for an hour through an electric flame of one thousand volts and 0.08 ampere. Four liters of the gases produce 0.75 gram of prussic acid.

Example II Nitrogen is at the normal temperature saturated with vapor of benzene in the proportion of nitrogen 92.1 per cent. and benzene (carbureted hydrogen) 7.9 per cent. and passed for one hour through the electric flame. In this case eight liters of gases give 0.48 gram of prussic acid, soot being at the same time deposited. The deposit of carbon may be prevented by the simultaneous passage of hydrogen.

Example III: A similar treatment with petroleum heated to from 35 to L0 centigrade yields in one hour 0.32 gram prussic acid.

Equal and sometimes better results are obtained if in lieu of free nitrogen nitrogen compounds, such as ammonia, be used. It is. not settled yet whether in the latter cases nascent hydrogen is evolved and produces at once prussic acid or whether the compounds of nitrogen and of carbon give rise to intermediate products, which yield prussic acid only in consequence of secondary reaction.

Example IV: Through an electric flame of twelve hundred volts and 0.07 ampere are simultaneously passed for a period of ten minutes two volumes of ammonia and one volume of acetylene, (or ethylene,) the volume of the gas being in each case four hundred centimeters and the pressure being seven hundred and twenty-five millimeters and tem perature 18 centigrade. \Vith acetylene the amount of prussic acid obtained is 0.23 gram; with ethylene it is 0.2 gram.

Other hydrocarbons may be used in place of acetylene and ethylene.

Having now particularly described and ascertained the nature of this invention and in what manner the same is to be performed, I declare that what I claim is 1. The manufacture of prussic acid by passing a gaseous mixture of nitrogen and hydrocarbon through a high-voltage electric flame, substantially as hereinbefore described.

2. The manufacture of prussic acid by passing a gaseous mixture of nitrogen, hydrogen and hydrocarbon through a high-voltage electric flame, substantially as described.

3. The manufacture of prussic acid, which consists in passing a gaseous mixture of nitrogen and hydrocarbon continuously through a high-voltage flame and removing the product formed, substantially as described.

4. The manufacture of prussic acid, which consists in passing a gaseous mixture of nitrogen and hydrocarbon continuously through a high-voltage flame and continuously removing the products formed, substantially as described.

5. The manufacture of prussic acid, which consists in passing a gaseous mixture of nitrogen, hydrocarbon and hydrogen continuously through a high-voltage flame and removing the products formed, substantially as described.

6. The manufacture of prussic acid which consists in passing a gaseous mixture of nitrogen, hydrocarbon and hydrogen continuously through a high-voltage flame and continuously removing the products formed, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

VVILHELM lWUTH MANN.

Vitnesses:

CLARA I. PARKER, Gnone KORNER.

It is hereby certified that the name of the assignee in Letters Patent No. 792,783, granted June 20, 1905, upon the application of Wilhelm Muthmann, of Munich, Germany, for an improvement in Manufacture of Prussic Acid, was erroneously written and printed The Roessler and Flasslacher Chemical Co., whereas the said name should have been written and printed The Roessler and Hasslacher Chemical 00.; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 16th day of January, A. D., 1906.

[emu] F. I. ALLEN,

Commissiorwr of Patents.

of nitrogen and of carbon give rise to intermediate products, which yield prussic acid only in consequence of secondary reaction.

Example IV: Through an electric flame of twelve hundred volts and 0.07 ampere are simultaneously passed for a period of ten minutes two volumes of ammonia and one volume of acetylene, (or ethylene,) the volume of the gas being in each case four hundred centimeters and the pressure being seven hundred and twenty-five millimeters and tem perature 18 centigrade. \Vith acetylene the amount of prussic acid obtained is 0.23 gram; with ethylene it is 0.2 gram.

Other hydrocarbons may be used in place of acetylene and ethylene.

Having now particularly described and ascertained the nature of this invention and in what manner the same is to be performed, I declare that what I claim is 1. The manufacture of prussic acid by passing a gaseous mixture of nitrogen and hydrocarbon through a high-voltage electric flame, substantially as hereinbefore described.

2. The manufacture of prussic acid by passing a gaseous mixture of nitrogen, hydrogen and hydrocarbon through a high-voltage electric flame, substantially as described.

3. The manufacture of prussic acid, which consists in passing a gaseous mixture of nitrogen and hydrocarbon continuously through a high-voltage flame and removing the product formed, substantially as described.

4. The manufacture of prussic acid, which consists in passing a gaseous mixture of nitrogen and hydrocarbon continuously through a high-voltage flame and continuously removing the products formed, substantially as described.

5. The manufacture of prussic acid, which consists in passing a gaseous mixture of nitrogen, hydrocarbon and hydrogen continuously through a high-voltage flame and removing the products formed, substantially as described.

6. The manufacture of prussic acid which consists in passing a gaseous mixture of nitrogen, hydrocarbon and hydrogen continuously through a high-voltage flame and continuously removing the products formed, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

VVILHELM lWUTH MANN.

Vitnesses:

CLARA I. PARKER, Gnone KORNER.

It is hereby certified that the name of the assignee in Letters Patent No. 792,783, granted June 20, 1905, upon the application of Wilhelm Muthmann, of Munich, Germany, for an improvement in Manufacture of Prussic Acid, was erroneously written and printed The Roessler and Flasslacher Chemical Co., whereas the said name should have been written and printed The Roessler and Hasslacher Chemical 00.; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 16th day of January, A. D., 1906.

[emu] F. I. ALLEN,

Commissiorwr of Patents.

Correction in Letters Patent No. 792.783.]

It is hereby certified that the name of the assignee in Letters Patent No. 792,783, granted June 20, 1905, upon the application of Wilhelm Muthmann, of Munich, Germany, for an improvement in Manufacture of Prussia Acid, was erroneously written and printed The Roessler and Flasslaoher Chemical 00., whereas the said name should have been written and printed The Raessler and Hasslaclm- Chemical Co.; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 16th day of January, A. D., 1906.

[SEAL] F. I. ALLEN,

Commissioner of Patents. 

